A fluidized electrocatalysis approach for ammonia synthesis using oxygen vacancy-rich Co3O4 nanoparticles

Abstract

We report a fluidized electrocatalysis system, composed of metallic titanium (Ti) mesh as the current collector and an aqueous ultrafine Co₃O₄ nanoparticle (NP) catalyst fabricated by the laser ablation in liquid (LAL) technique, for the efficient electrocatalytic nitrogen reduction reaction (NRR) to ammonia (NH₃) synthesis. The results indicated that utilizing this fluidized electrocatalysis system, the LAL-fabricated ultrafine Co₃O₄ NPs highly dispersed in 0.1 M Na₂SO₄ solution (pH = 10.5) exhibit high NRR activity, affording an NH₃ yield rate of 235.0 μg h⁻¹ mg_cat.⁻¹ and a faradaic efficiency (FE) of 16.3% at −0.30 V (vs. RHE). The superior NRR performance can be ascribed to the fluidized electrocatalysis approach to take full advantage of the exposed oxygen vacancies as active sites of Co₃O₄ NPs for N₂ adsorption and activation.